Tube-swaging and thread-rolling apparatus



July 20, 1954 J. w. CLERKE TUBE-SWAGING AND THREAD-ROLLING APPARATUS Filed April 28, 1950 4 Sheets-S111)v l INVENTOR.

JOHN W. LERKE BY AW ORNEY.

July 20, 1954 J. w. CLERKE TUBE-SWAGING AND THREAD-ROLLING APPARATUS Filed April 28, 1950 4 Sheets-Sheet 2 INVENTOR.

JOHN W. CLERKE Q AWL ATTORNEY.

\t i/ v N Am 8 July 20, 1954 J w, KE 2,684,101

TUBE-SWAGING AND THREAD-ROLLING APPARATUS Filed April 28, 1950 4 Sheets-Sheet 3 m1 II/l Til "mi O m N 00 a K M m .N g 2:

o I /\/\1 Q g a g -L t K, j ii & HIIIIII q .0 a; a k

INVENTOR.

JOHN W. CLERKE ia m ATTORNEY y 20, 1954 J. w. CLERKE 2,684,101

TUBE-SWAGING AND THREAD-ROLLING APPARATUS Filed April 28, 1950 4 Sheets-Sheet 4 MW w INVENTOR.

JOHN W. CLERKE ATTORNEY.

Xv Mm Patented July 20, 1954 TUBE-SWAGING AND THREAD-ROLLING APPARATUS John W. Clerke, Little Falls, N. J.

Application April 28, 1950, Serial No. 158,645

8 Claims.

This invention relates to thread-forming apparatus and more particularly to apparatus for forming rolled threads in an end portion of a section of tubing that may be made of a suitable metal, such as stainless steel or the like.

It is a primary object of the invention to pro vide an improved tool or apparatus for forming rolled threads in an end portion of a section of tubing.

Another object of the invention is to provide apparatus for successively swaging and forming rolled threads in a tubular member.

The invention has for another object the btaining of an effective fluid-tight seal between complementary tubular elements having matching threads rolled therein by apparatus con-- structed in accordance with this invention.

Another object of the invention is to provide an accurate, uniform and smooth rolled thread form having improved characteristics.

Another object of the invention is to provide a portable tool adapted to be readily joined to an end portion of a length of tubing, such as stainless steel, swage such end portion of the tubing, form rolled threads in the swaged tubing, and be subsequently withdrawn from the tubing.

Another object of the invention is to provide an improved mandrel for swaging an end part of a length of tubing. v

A further object of the invention is to provide a mandrel peripherally configured so as to co.- operate with other devices in the ready forma tion of rolled threads in tubing.

A still further object of the invention is to provide apparatus of the character indicated that is adapted to perform its intended functions in an effective and trouble-free manner.

To the end that the foregoing objects may be attained, a recommended and preferred form of apparatus constructed in accordance with the invention includes a first unit comprising a. body and thread-rolling means carried by the body,

and a second unit comprising a feed screw threadedly connected to the body and a mandrel.

The mandrel includes a first part or shank coaxial with and threadedly connected to the feed screw, a second or intermediate part that is grooved peripherally for coaction with the thread-rolling means in the formation of rolled threads in the tubing, and a third or pilot part adapted to be initially introduced into the tubing. The mandrel shank is normally keyed to the feed screw to prevent relative movement therebetween.

When the apparatus is intended for use to both swage and form rolled threads in the tubing, a

portion of the mandrel second part remote from the shank is tapered inwardly in the direction of the pilot part. To facilitate swaging of relatively large diameter and/or thick-walled tubing, there is provided a plurality of swaging balls movable in radial passages formed in the mandrel second part. The position of the swaging balls is controlled through the medium of a central or sizing ball, a rod slidable in the mandrel, and associated devices, as will be explained in the detailed description further along herein.

Relative movement between the first and second units is prevented by a latch means that includes a member or rod carried by and slidable in the body and registering with an opening in the feed screw. This rod is normally urged in the direction of the feed screw by a spring which. acts to maintain the rod in engagement with the feed screw. The rod is adapted to be moved in a reverse direction against the action of the spring by an arrangement of devices whereby to effect disengagement between the rod and the feed screw, as desired, and thereby permit relative movement between the body and the feed screw.

In the case of relatively small diameter and thin-walled tubing, the swaging balls and control devices therefor may be omitted. A portion of the second part of the mandrel may be tapered, as indicated above, when the apparatus is to be used for the purpose of both swaging and forming rolled threads in the tubing. If the apparatus is intended for use to form the rolled threads only, it is recommended that the second part of the mandrel be substantially uniform in cross section and of such size as to permit a snug gripping fit with the inner surface of the tubing so as to prevent relative movement between the mandrel and the tubing during the thread-rolling operation.

The enumerated objects, as well as additional objects, together with the advantages of the invention, will be readily understood by persons skilled in the art upon reference to the following detailed description, taken in conjunction with the accompanying drawings that respectively describe and illustrate preferred embodiments of the invention.

In the drawings:

Figure 1 is a View in side elevation of a combined tube-swaging and thread-rolling apparatus constructed in accordance with the invention;

Figure 2 is a top plan view of the apparatus shown in Figure 1;

Figure 3 is an enlarged side elevational View of 3 a plunger that is adapted to cooperate with other devices in controlling the position of a plurality of tube-swaging balls;

Figure 4 is an enlarged fragmentary View taken along line l of Figure 2;

Figure 5 is a view in enlargement taken along line 55 of Figure 2, and additionally shows the pilot part of the mandrel positioned. in an end portion of a section of tubing:

Figure 6 is a View taken along line 6-6 of Figure 5;

Figure 7 is a view taken along line l'! of Figure 5;

Figure 8 is a View corresponding to Figure 5,

and shows another relative position of the tool of the invention with respect to the section of tubing. In this figure, the parts are shown at the completion of the swaging operation'but before the thread-forming operation;

Figure 9 is another View corresponding to Figure 5, and showsthe relative position of the parts at the completion of both the swaging and thread-forming operations;

Figure 10 illustrates a modified form ofthe invention and corresponds generally to Figure 5;

Figure 11 shows the parts in the lowerportion of Figure 10 in another relative position, and corresponds generally toFigure 8; and

Figure 12 illustrates the apparatus of Figure 10 in another relative position with respect to a tubing section, and corresponds generally to Figure 9.

Referring now to the drawings, wherein like reference numerals denote corresponding parts throughout the several views, a hollow body 15 is formed with a threaded longitudinal central opening it and a merging recess i? at its upper end. Body 15 is provided at its lower end with'a flange l3, and at its upper end with a plurality, preferably three, equi-angularly spaced, radiallyprojecting, tapped bosses 29, 2! and 22.

A feed screw 23 having a head 25 threadedly engages threaded opening H5 in the body. The feed screw is machined to obtain an axial tapped opening 25, a transverse blind bore 25 in head 24, and an opening 2! coaxial with opening 25 and communicating with opening 25 and bore 25.

A third roll assembly or means-3t, best shown in Figures 5 and 6, comprises a housing consistingof a pair of relatively inverted members 3! and 32. Member 3i includes a downwardly projecting flange 33, a plurality, preferably three, downwardly projecting tubular extensions 34, and a central opening 35. Member 32 is generally the same in construction as member 3!, and includes an upwardly projecting flange 36, a corresponding number of upwardly projecting tubular extensions 31, and a central opening 38. A shaft or trunnion id is press-fitted in each extension 34 and corresponding extension 37. Freely rotatable about each shaft in is a cylindrical thread roller 4! having integral annular thread-rolling elements 42. The axis of each shaft 559 and, therefore, the axes of corresponding thread rollers i! and thread-forming elements 42 are inclined with respect to the axis of feed screw 23 so as to cooperate with other devices, to be described further along herein, in the formation of helical threads. The thread-rolling assembly housing is attached to body flange l5 and maintained in the illustrated position through the medium of studs t3 and spacer sleeves 44.

Reference is next had to Figures 5 and 7 for details of construction of a mandrel 45 that that defines the outer extremity of a generally helical groove 49. The lower portion of inter- .mediate part s8 is tapered downwardly and inwardly and merges with pilot part 4?, as best shown in Figure 1.

The mandrel is provided with coaxial longitudinal central openings 50 and 5| that are in axial alignment with openings 25 and 27 when the apparatus is assembled. Slidable in opening 50 and extending at its opposite ends into openings 5! .and 27 is a rod 52. The tapered portion of the mandrel is provided with a plurality'of spaced radial passages 53, each of which is adapted to accommodate a swaging ball 56, preferably made of a suitable hardened steel. A steel sizing or adjusting ball is movable in mandrel opening .5 l and bears against each swaging ball 54. An adjusting screw 56 retains sizing ball 55 within themandrel and limits downward movement of that ball in opening 5i. Screw 56 is maintained .in desired adjusted position bya lock nut 51. which bears against the lower extremity of the mandrel.

The apparatus of this invention is adapted to swage and rolla thread in an end-portion of a section of tubing 53. The major diameter of pilot part 4] is slightly less than the internal diameter of tubing .53 to permit ready insertion of the same into the tubing. The diameter of the portion of intermediate mandrel part 48 be low swaging balls 54 is slightly greater than the internal diameter of the tubing, while the diameter of the intermediate mandrel part above the swaging balls is greater than the internal diameter of the tubing.

Concentric with themandrel is a sleeve 60 that bears at its upper .end against the lower end of feed screw 23 and at its lower end against the upper end of intermediate mandrel part 46. The outer diameter of the sleeve is slightly greater than the maximumdiameter of the intermediate mandrel portion but is smaller than the diam eterof housing openings 35 and 33.

A screw 61 (Figure 4) base pin extension 62 which registers with an'opening 63 defined by feed screw 23 and mandrel shank lfi. Screw 5| serves to .key the mandrel to the feed screw and prevent movement of the mandrel with respect to .the feed screw during the swaging and threadrolling operations.

A plunger 65, best shown in Figures 3 and 5, is reciprocable in bore 26. This plunger comprises a body 66 and an integral forward spring guide 61 that forms ashoulder 68 with-the body. The

- body is provided with an upper slot 68 that is adapted to receivea retainingscrew it that permits axial movement but prevents rotational movement of the body with respect to bore 26. Plunger body 66 has a lower slot H and an inclined camming surface T2. A helical compression spring 13 bears against body shoulder 58 and normally and yieldingly urges the plunger toward the right, as viewed in Figure 5.

When plunger 55 is in the relative position shown inFigure 5, the upper extremity of rod 52 bears against the portion of the body 66 to the right of camming surface 72, sizing ball 55 is in protracted position as allowed by adjusting screw 56, and swaging balls 54 are in protracted position in their respective passages. When the plunger is in the position shown in Figure 9, spring 73 will have moved the plunger toward the right to the extent allowed by screw 18 and the upper extremity of rod 52 extends into lower slot H, permitting swaging balls 54 and sizing ball 55 to be retracted in their respective passages.

Reference is next had to Figures 2, and 9 for an understanding of a combined handle and latch means or mechanism for controlling relative movement between the body and the feed screw and for coaction with earlier described devices for controlling the position of swaging balls 54 and sizing ball 53. This mechanism includes a. tubular member 19 externally threaded at one end for connection with a tap in boss 28. A member or rod H is rotatable and slidable in tubular member 16 and has a flange 18 that is positioned in a spring compartment 19 formed in boss 28. A helical compression spring 89 is coaxial with rod Tl and bears at its opposite ends against fiange l5 and tubular member 16 to normally urge rod 1'! toward the left, as viewed in Figure 5. The inner end of rod H is movable into and out of registry with feed screw bore 26 and is maintained in registry with the bore by spring 80.

The outer end of rod 11 registers with an opening 9| in a knurled cap 82 and is secured to the cap by a pin 83. The cap is notched, as indicated at 84 (Figure 2), to receive a pin 85 carried by tubular member 19. The cap has a camming surface 86 that defines part of notch 85.

For the purpose of effecting disengagement between rod H and feed screw 23, cap 82 is gripped and moved toward the right against the action of spring 88, as viewed in Figure 5. This causes rod 11 to be moved toward the right and withdrawal of the inner end of the rod from bore 26 until the parts are in the relative position shown in Figure 9. When the parts are in the position of Figure 9, body I5 may be moved relative to feed screw 23. Upon movement of rod 11 to the position shown in Figure 9, notch 84 is placed out of registry with pin 85, and by giving cap 82 about a quarter turn about its axis, the open end of the cap will bear against pin 85 and maintain the rod in retracted position.

Bosses 2i and 22 are provided with corresponding handles 81 and 88 which may be solid rods or tubular elements externally threaded at their inner ends for connection with corresponding taps (not shown) in the bosses.

For the purpose of briefly outlining the mode of operation of the above described embodiment of the invention, it is first assumed that the parts are assembled and in the relative position shown in Figure 5 so that the inner end of rod 11 registers with bore 26, thereby locking body IE to feed screw 23; plunger 65 is at its extreme left position as allowed by screw 18 and against the action of spring [3; rod 52 and sizing ball 55 are at their lowermost positions as allowed by adjusting screw 56; swaging balls 54 are protracted outwardly in their respective passages by sizing ball 55; and mandrel pilot part 41 is in the upper end. of tubing section 58, which is held in a vise or the like (not shown). With the parts as illustrated and described, ridge 49 of the lower tapered part of the mandrel grips the inner surface of tubing 58.

The tool is then rotated in a clockwise direction, as viewed in Figure 2, by means of handles 75, 87 and 8B, which causes helical ridge 49 to bite into and feed the mandrel into the tubing and swaging balls 54 to expand the upper portion of the tubing until the parts are in the relative position shown in Figure 8, at which time the upper part of the tubing has been expanded and its upper extremity bears against the lower end of sleeve 59, which limits movement of the mandrel in the tubing. This completes the swaging operation.

Cap 82 is next moved toward the right and against the action of spring 88, as viewed in Figure 8, and simultaneously given about a quarter or half turn about its axis. This retracts the inner end of rod 11 from bore 29 and places notch 84 out of registry with pin 85. The cap may then be released, and its open end will bear against pin 8'5, maintaining rod H out of engagement with the feed screw against the action of spring 88, as indicated in Figure 9.

Retraction of rod 1'! from bore 25 permits spring 13 to move plunger 55 toward the right from the position shown in Figure 8 to that shown in Figure 9. This allows swaging balls 54 to move inwardly and sizing ball 55 and rod 52 to move upwardly.

The handles are again actuated to impart further clockwise rotation to body l5, as viewed in Figure 2. This causes body [5 to turn and move downwardly with respect to screw 23 and thread rollers 4! to cooperate with groove 49' in the mandrel to roll threads in the swaged portion of tubing 58 (Figure 9).

The tool may be readily withdrawn from tubing 58 by rotating body l5 in a reverse direction, which permits the body to move upwardly with respect to the feed screw and then permits the mandrel to'be unscrewed from the threads previously rolled in the tubing. Rod 17 is maintained in the position shown in Figure 9 during this operation to prevent entry of its inner end in bore 28 and protraction of swaging balls 54 in ieir passages.

In Figures 10-12, there is shown a modified form of the invention which is the same as the earlier described embodiment with the exception that it contemplates the substitution of a mandrel 99 for mandrel 45. Mandrel 98 comprises a shank or first part 9i coaxial and in threaded engagement with feed screw 23, a cylindrical pilot part 92 that is slightly smaller in cross section than the inner diameter of tubing 58, and an intermediate part 99 formed with a helical ridge 94 and a helical groove 94' corresponding to ridge 29 and groove 59' of mandrel 35. Ridge 95 and groove 95' are preferably elements of a true helix defined in a surface of revolution of a right circular cylinder that is slightly greater in diameter than the inner diameter of tubing 58.

If desired, the lower portion of intermediate mandrel part 93 may be tapered downwardly as in the case of mandrel 45. The mandrel of Figures 19-12 is intended for use with relatively small diameter thin-walled tubing, whether intermediate part 93 is as shown or is tapered for swaging purposes.

The operation of the form of the invention shown in Figures l0-12 is generally the same as that described in connection with the embodiment shown in Figures 1-9.

"From the foregoing, ;it is believed that the construction, operation, andadvantages of my present invention will be readily comprehended by persons skilled in the art. It is to be clearly understood, however, thatvarious changes in the apparatus set forth above may be-made without departing from the scope of .the invention, it being intended that all matter contained. in the description or shown in the drawings shall be interreted as illustrative only and not in a limiting sense.

I claim:

1. Inapparatus of the character described, a first unit comprising a body and thread rolling meanscarried by the body, a second unit comprising a feed screw lthreadedly connected to the body and a mandrel. including a first part or shank connected to the feed screw and a second part adapted to be introduced into an end portion of a section of tubing, said second part being grooved peripherally for ccaction with "the thread-rolling means in the formation of rolled threads the tubing, said second part having a plurality of angularly spaced, inwardly extending radial openings, a swaging element movable in each opening and-adjustable means controlling inward movement of the swaging elements in their-openings, latch means preventing relative movement between the body and the feed screw and coacting with the adjustable meansto limit inward movement of the swaging elements in their openings, said latch means comprising a member carried by and iricvable with respect to the body and releasably engaging the feed screw, and means for actuating the member in-a manner to eifectdisengagement *etwee the member and the feedscrew to permit relativc movement between the body and the feed screw-and for releasing the adjustable means to permit further inward movement of the swaging elements in their openings.

2. Apparatus in accordance with claim l where in 'each swaging element is spherical and the adjustable means includes a ball movable in an axial passage formed in the mandrel.

3. Apparatus in accordance with claim 1 wherein the adgustable means comprises a rod movable in an axial passage formed in the mandrel, a -spring-pressed plunger slidable in the feed screw and having one end in engagement with the rod, said plunger being maintained in a predetermined position by the .member and being movable to another position in response to disengagement of the member from the feed screw.

'4. Apparatus in accordance with claim 3 wherein each swaging element is spherical and the adjustable means further includesa ball movable in an axial passage formed in the mandrel and bearing against each'swaging element and against the end of the rod remote from the plunger.

5. A mandrel'of the character indicated comprising a first or shank part and second part coaxial with and constituting a continuation of the first part, said second part havinga generally helical peripheral-groove formed therein, portions of the second part defining the groove forming a generally helical ridge that is adapted to effect firm gripping engagement with the interior of a length of tubing upon introducing the second part in an end of the tubing and imparting angular movement in one direction and axial movement in a corresponding direction to .the mandrel With respect'to the tubing, said second part having a plurality of angularly spaced, inwardly extending radial openings, a swaging'element movable in each opening, and adjustable means controlling inward movement of each swaging element in the corresponding opening wherein each swaging elementvis spherical and the adjustable means includes a ball movable in an axialpassage formed in the second part.

6. A mandrel of the character indicated com prising a first or shank part and a second part coaxial with-and constituting a continuation of the first part, said second part having a generally helical peripheral groove formed therein and axially coextensive therewith, the groove defining srniace of-thesecondpartbeing so configured as to form a generally helical ridge, said second part comprising a first portion adjacent the shank part and substantially uniform in cross section area and a second portion .merging with the end of the-first portion remote from the shank part and tapering inwardly in a direction away from the shank part, said second part having a plurality of angularly spaced, inwardly extending radial openingaa swaging element movable in each opening, and adjustable means controlling inward movementof each swag'ing element in the corresponding opening.

.7. A mandrel in accordance with claim 6 wherein each swaging element is spherical and theladjustable means includes a ball movable in an axial passage formed in the secondpart.

8. A mandrel in accordance with claim 7 wherein the helical ridge is substantially V- shaped.

Beferences Cited in the file of this patent UNITED STATES PATENTS Number Name Date 497,820 Robertson May 23, 1893 598,278 Bailey Feb. 1, 1898 2,167,558 Upson July '25, 1989 2,345,871 Hallberg Apr. 4, 19%

2,476,656 Galbraith July 19, 1949 

